Fuel control for internal combustion engines



April 18, 1939. R. M. ANDERSON 2,154,417

FUEL CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Now. 6, 1937 I -/2 3/ 27 9 r a? 1 mvsmon PA YNO/VD M A N-DERSON BY FM ATTORNEYS Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE FUEL CONTROL FOR- INTERNAL COHBUS- TIQN ENGINES Raymond M. Anderson. Detroit, Mic-.11., asaignor of one-half to Heights, Ohio D. Church, Cleveland This invention relates broadly to hydrocarbon motors and more specifically to apparatus for controlling the temperature-pressure and volume of the fuel mixture during the periods of 5, operation of the engine when the throttle is positioned in partly open adjustment.

As is well known in the art, when the carburetorthrottle of an-internal combustion engine is nearly closed, as in idling, a sub-atmoslu pheric pressure is created in the intake manifold which imposes a load upon the engine proportional to the vacuum. Thus in the normal operation of an engine at low speeds the power required to turn the motor over is relatively high,

- and less fuel per delivered horsepower hour is required as the throttle position approaches wide Open adjustment.

Efforts have been made heretofore to improve the fuel economy of hydrocarbon engines and reduce the vacuum load or 'so called pumping loss therein. These efforts have been directed generally to the provision of a relatively small hole in the intake manifold whlchpermitted the admission of ambient air to dilute the fuel mixture, and also reduced the cylinder and manifold In thepresent invention the principle of fuel mixture dilution is employed, but instead of admitting a constant charge of air to the intake manifold gases are taken from the exhaust manlfold at a point where the temperatures are 4.0 relatively high and a restricted volume of air is substituted therefor. sion of such diluent is metered by a valve mechanism operatively controlled by the sub-atmospheric pressure in the intake manifold which in 5 turn is governed by the carburetor throttle during certain periods of operation of the engine. With such device it will be recognized that the function of the carburetor, as a proportloning device forair and fuel will be unaltered although 50 dilution of the fuel mixture produced thereby will be effected at certain throttle positions.

Referring to the drawing:

Fig. 1 is a vertical section through a fragmentary portion of a carburetor. an exhaust manl- 65. fold of thetype in which a" portion of the in- In addition the admistake pipe is incased by the exhaust manifold v and the valve mechanism embodying the present invention; and I Fig. 2 is a vertical section through a fragmentary portion ofa manifold of the above type 6 and a modified form of the valve mechanism 11 lustrated in Fig. 1.

Referring first to Fig. 1, the carburetor 10, which as illustrated comprises a float chamber lba, jet llb, primary venturi lie and secondary 10 venturl lld connected to the intake pipe ll mounted on the intake manifold l2, which as illustrated herein is formed with a portion there-. of enveloped by the exhaust pipe i3. Within the intake pipe ll intermediate the carburetor. and 16 intake manifold l2 there is a throttle valve ll operatively controlled by linkage (not shown) of the type in general use in automobile construction. The intake pipe II is formed with a port l8 disposed on the carburetor side of the throttle valve It in a plane substantially normal to the axis thereof and in juxtaposition with the peripherial edge of the valve in its closed 'or idling the operating mechanism therefor.

The exhaust pipe I3 is formed with a boss is having an opening 2| therein in axial alignment with a valve seat 2| in the intake manifold l2. Within the opening 20 there is a valve guide housing 22 for the support of a reciprocative valve plunger 28 which is formed with a conical end portion engageable with the valve seat 85 2|. The opposed end of the valve plunger 23 is connected to a diaphragm 24 having the peripheral edge thereof mounted in a housing 25. Upon the outer face of the diaphragm housing there is a frame 28 dulled and tapped to receive a coupling for the conduit i1 and bored for the reception of a compression spring 21 which is impinged betweenthe diaphragm 24 and the end wall of the bore. A port 28 is provided in the outer end of the frame 25 to facilitate fluid com- I. is formed with a cylindrical extension ll, the outer end of which is machined to snugly engage, as with a light drive fit, the opening 42 in the intake manifold l2. The outer diameter of the cylindrical extension 4| is constructed so that theopening 42 may be formed by the tap drill employed when machining the boss 43 in the exhaust manifold I3 though it is to be understood that the external diameter of the cylindrical extension is not essentially limited to such size or construction. The end of the extension 4| is formed with a shoulder 44 chamfered upon its inner face to form a valve seat 45 for the conical end of the valve plunger 46. The end of the valve plunger is provided with a reduced shank portion 41 to facilitate the circulation of the gas or the burnt products of combustion admitted through transverse openings 48 in the'cylindrical extension 4| and the port 49 in the shouldered end 44 of the cylinder. The valve plunger 45 is machined with a longitudinal bore 50 which communicates with a transverse opening 5|, and an annular groove 52 arranged for communication with a port 53 upon reciprocation of the valve plunger 46 so that atmospheric air will be commingled with the exhaust gas when the valve 46 is lifted off its seat. The outer end of the plunger 50 is connected to a diaphragm 55 having the peripheral edge thereof mounted between the flanged portions 56 of the diaphragm housing The outer end of the housing 40 is bored to receive a helical spring 21 retained in compressive adjustment against the diaphragm 55 by a nut 58 mounted in the end portion ofthe housing 40. The nut 58 is tapped to receive a fitting for the support of the tube l1 and is drilled to afford fiuid communication between intake pipe and the chamber defined by the housing 40 and diaphragm 55. e

In operation when the throttle valve I4 is progressively opened beyond the idling position varying percentages of subatmospheric pressurein the intake pipe are transmitted through the conduit II to the chamber in the outer end of the diaphragm housing where they overcome the force of the spring 21, and thus effect the retraction of the valve plunger from its seat. As the valve is opened gases from the exhaust manifold will be admitted to the intake pipe where they will commingle with the air admitted through I the bore 29 in the plunger valve, and thus cause dilution of the fuel mixture, reduction of the sub-atmospheric pressure in the intake pipe H and reduction of the pumping losses of the engine. Moreover, the introduction of hot exhaust gases in the intake pipe will cause the expansion of the fuel mixture and thus increase the velocity and atomization of the charge delivered to the cylinders of the engine. The atmospheric air admitted through the passage 29 (Fig. 1) in ,the plunger valve affords further dilution of the fuel mixture in the intake pipe and in addition prevents the portion of the plunger valve which is engaged with the valve seat 2| from being r overheated and unduly carbonized.

an exhaust pipe surrounding a portion of the intake pipe, mechanism to reduce the vacuum in said intake pipe during the operation of said engine comprising a valve adapted to admit exhaust gas and atmospheric air to said intake pipe, a pressure responsive device operatively connected to said valve, a conduit connected with said pressure responsive device and with said intake pipe, said conduit being disposed in relation to said throttle to effect communication between said pressure responsie device and said intake pipe as said throttle is open.

2. In an internal combustion engine embodying an intake pipe having a throttle therein and an exhaust pipe surrounding a portion of said intake pipe for heating a portion thereof, mechanism for reducing the vacuum in the intake pipe during the operation of the engine comprising a valve in the intake pipe adjacent said connection with the exhaust pipe, fluid means for operating saidgvalve to admit a diluent of exhaust gas and air into said intake pipe, said fluid means being controlled by said throttleto open said valve as said-throttle is adjusted toward its open position.

3. In an internal combustion engine embodying an intake pipe having a throttle therein and and means coordinated with said throttle for opening said valve coincident the initial opening of said throttle and a spring for closing said valve as the throttle approaches its open position.

4. In an internal combustion engine embodying an intake pipe having a throttle therein and an exhaust pipe surrounding a portion of the intake pipe, mechanism to reduce the piston pumping load in said engine during the operation thereof comprising a valve adapted to admit exhaust gas and .air into said intake pipe, vacuum responsive means connected with said valve, a. conduit connecting said vacuum responsive means withsaid intake pipe, said conduit being disposed in said intake pipe in juxtaposition with said throttle, whereby fluid communication to the engine side of said intake pipe is closed when said throttle 'is adjusted inits closed position and open when said throttle is adjusted in its open position,

5. In an internal combustion engine embodying an intake pipe having a throttle therein and an exhaust pipe surrounding a portion of said intake pipe for heating a portion thereof, mechintake pipe comprising a valve for admitting exhaust gas into said intake pipe, vacuum operated means controlled by said throttle for operating said valve, said valve being arranged to admit hot exhaust gas and atmospheric air to said intake pipe to effect the atomization of the fuel mixture therein.

6. In an internal combustion engine embodying an intake pipe having a throttle therein and an exhaust pipe surrounding a portion of said intake pipe for heating a portion thereof, mechanism for the dilution of the fuel mixture in said intake pipe comprising a valve for admitting exhaust gas into said intake pipe, vacuum operated anism for the dilution of the fuel mixture in said means controlled by said throttle for operating said valve, said valve being arranged to admit hot exhaust gas to said intake pipe ifor effecting the atomization oi the fuel mixture therein and means to facilitate the admission of atmospheric air into the intake pipe in the zone controlled by said valve.

'1. In an internal combustion engine embodying an intake pipe having a throttle therein and an exhaust pipe, mechanism for reducing the vacuum in said intake pipe during the operation 01 the engine comprising a valve adapted to admit exhaustgas and air into said intake pipe, said valve having a longitudinal bore therein having iiuid communication with atmosphere, vacuum controlled operating mechanism therefor, a conduit connecting said operatingv mechmm with said intake pip the opening therein being disposed adjacent the throttleplate on the carburetor side thereof, whereby said operating mechanism will eilect the opening of said valve upon opening of said throttle and open communication or the longitudinalbore with atmosphere for cooling the end portion or said valve.

8. In an internal combustion engine embodying an intake pipe having a throttle thereinand an exhaust pipe, mechanism for reducing the vacuum in said intake pipe during the operation of the engine comprising a valve having a longitudinal bore therein adapted to admit exhaust gas and air into said intake pipe, the atmospheric air being admitted through said bore for cooling said valve, vacuum controlled operating mechanism therefor, a conduit connecting saidoperating mechanism with saidintake pipe, the opening therein being disposed adjacent the throttle plate onthe'carburetor side thereof, whereby the vacuum in said intake pipe will actuate said operating mechanism as said throttle is 4 opened.

RAYMOND M. ANDERSON. 

